A White Paper on the status and needs of tilapia aquaculture in the North Central Region

Tilapias are grown in many states in the North Central Region (NCR), and the group has been designated as high priority by the North Central Regional Aquaculture Center (NCRAC) Industry Advisory Council (IAC). Tilapias are essentially only grown in indoor water recirculating aquaculture systems (RASs) in the region. Each year, priority research areas are identified by the NCRAC IAC and presented in consultation with the Technical Committee to the NCRAC Board of Directors (Board). Concern has emanated among the various NCRAC constituencies that work plans could potentially lose focus over time and not always address the most critical factors limiting the economical and sustainable production of important species in the region. After discussions were held among members of the various committees and the Board at its February 1998 annual meeting, it was decided that a white paper should be developed on tilapias

A White Paper on the status and needs of hybrid striped bass aquaculture in the North Central Region

The hybrid striped bass is a cross between the anadromous striped bass Morone saxatilis and the freshwater white bass M. chrysops. Hybrid striped bass are grown in several states in the North Central Region (NCR), and the group has been designated as high priority by the North Central Regional Aquaculture Center (NCRAC) Industry Advisory Committee (IAC). Each year priority research areas are identified by the NCRAC IAC and presented in consultation with the Technical Committee to the NCRAC Board of Directors. Concern has emanated among the various NCRAC constituencies that work plans could potentially lose focus over time and not always address the most critical factors limiting the economical and sustainable production of important species in the region. After discussions were held among members of various committees and the Board at its June 1999 meeting, it was decided that a white paper should be developed on hybrid striped bass

Comparison of Bluegill Consumption Rates by Largemouth Bass and Sunshine Bass in Structured and Nonstructured Artificial Environments

We compared consumption rates of bluegills Lepomis macrochirus by largemouth bass Micropterus salmoides and sunshine bass (female white bass Morone chrysops × male striped bass M. saxatilis) in structured (about 50% coverage with artificial vegetation) and nonstructured 2,000-L fiberglass tanks. In the presence of structure, instantaneous bluegill mortality from consumption by largemouth bass was significantly higher than that caused by sunshine bass but was similar when structure was absent. Instantaneous bluegill mortality from consumption by wild largemouth bass was significantly higher than by pellet-trained largemouth bass in both structured and nonstructured environments. When pellet-trained sunshine bass served as the predator, bluegill instantaneous mortality rate was similar within structured and nonstructured environments. Our findings indicate that sunshine bass are not as adept as largemouth bass at consuming bluegills in the presence of structure but that, unlike largemouth bass, their consumption rates on bluegills are not affected by prior predatory experience

Assessment of Floating Vertical Raceways for the Culture of Phase-II Hybrid Striped Bass

A floating vertical raceway is a system designed to provide a constant, unidirectional flow of water to fish confined in a flexible raceway that is suspended vertically in the water column. This study evaluated the potential of floating vertical raceways for the culture of phase-II sunshine bass (female white bass Morone chrysops × male striped bass M. saxatilis) reared at two densities (125 and 188 fish/m3). Fish with a mean starting weight of 0.7 g were fed a diet containing 40% crude protein to satiation for 121 d. Fish in the low-density treatment reached a significantly higher final mean weight (160.0 g) than those in the high-density treatment (136.9 g). Survival was also significantly higher in the low-density treatment (81.1%) than in the high-density treatment (73.8%). No significant differences in water quality were detected for dissolved oxygen, total ammonia, un-ionized ammonia, or temperature between high-density and low-density treatments. Unlike the surrounding reservoir, water temperature inside the raceways remained destratified throughout the growing period. Based on the performance of fish, the high water quality maintained inside the enclosures, and ease of use, the floating vertical raceway system offers considerable promise as an alternative rearing system for deepwater impoundments

Cold Tolerance and Fatty Acid Composition of Striped Bass, White Bass, and Their Hybrids

Cold tolerance of striped bass Morone saxatilis, white bass M. chrysops, palmetto bass (female striped bass × male white bass), and sunshine bass (female white bass × male striped bass) were compared under controlled laboratory conditions. Two groups of each taxon were acclimated at 20°C in a recirculating-water system housed in an environmental chamber and were fed either a natural or prepared diet for 84 d. The fatty acid composition of the natural diet was 13% more unsaturated than that of the prepared diet. Fish fed the natural diet subsequently had unsaturated:saturated fatty acid ratios 10–25% higher than fish fed the prepared diet. After being subjected to identical simulated cold fronts (10°C drop in surface water temperature, as if the fish were confined in cages or pens), all groups of fish fed the prepared diet suffered high mortality (50–90%) whereas there was zero mortality among the groups receiving the natural diet. White bass and sunshine bass fed the prepared diet had higher survival rates (50% and 40%, respectively) compared with their striped bass and palmetto bass counterparts (10% and 20%, respectively). The lower incipient lethal temperature was higher for fish fed the prepared diet (5.9, 4.8, 2.5, and 1.9°C for striped bass, palmetto bass, sunshine bass and white bass, respectively) than for those fed the natural diet (near 0.0°C, but 1.8°C for sunshine bass). Both studies reflect a maternal affect on cold tolerance, with white bass being most tolerant. We demonstrated that diet-induced muscle fatty acid composition directly affects cold tolerance of striped bass, white bass, and their hybrids

Acute Responses to Salinity for Sunshine Bass and Palmetto Bass

Differences in salinity tolerance and osmoregulatory performance between sunshine bass (white bass Morone chrysops ♀ × striped bass M. saxatilis ♂) and palmetto bass (striped bass ♀ × white bass ♂) were evaluated by using direct-transfer toxicity testing and monitoring of plasma osmolality during salinity elevation. The 24-h LC50 (concentration lethal for 50% of test animals) for sunshine bass was a salinity of 27.9‰ with a 95% lower and upper confidence interval (CI) of 24.5‰ to 36.2‰. The 24-h LC50 for palmetto bass was 28.0‰ with a 95% CI of 26.2‰ to 30.8‰. Test temperatures during this interval ranged from 19.6°C to 21.7°C, and the LC50 values for both crosses did not differ significantly. Differences in osmoregulatory performance were determined by sampling blood plasma osmolality (mmol/kg) during a stepwise elevation in salinity from freshwater to 52‰. Plasma osmolality of sunshine bass was significantly higher at 11‰, but osmolality of palmetto bass was higher at 41‰ and 52‰. Sunshine bass maintained baseline plasma osmolality through 41‰, whereas palmetto bass could only maintain baseline osmolality through 31‰. Although both crosses have similar tolerance to increasing salinity in terms of survival, sunshine bass appear to tolerate osmoregulatory stress better than palmetto bass, based on blood plasma osmoregulation

Aquaculture Performance Comparison of Sunshine Bass, Palmetto Bass, and White Bass

Aquaculture performance of phase II and phase III sunshine bass (a female white bass Morone chrysops × male striped bass M. saxatilis), palmetto bass (a female striped bass × male white bass), and white bass were evaluated in separate 12-week yield trials conducted in indoor recirculating-water systems. Phase II sunshine bass, palmetto bass, and white bass had mean initial weights of 40.0 g, 39.7 g, and 41.0 g, respectively. A diet containing 40.2% crude protein (CP) was fed to fish twice daily at a rate of 3% body weight/d. At the end of the trial, sunshine bass and white bass had mean weights of 124.2 g and 126.0 g, respectively and were significantly larger than palmetto bass (93.5 g mean weight). Phase II sunshine bass and white bass outperformed palmetto bass by having higher relative growth (h), mean daily growth, and relative weight, as well as better feed conversion ratios (weight of food fed/weight gained). Survival was 100% for all three taxonomic groups. In the phase III study, mean initial weights for sunshine bass (177.5 g) and palmetto bass (185.9 g) were similar but significantly greater than the mean initial weight of white bass (153.8 g). In this trial, fish were fed a floating trout chow (44.1% CP) to satiation twice per day. At the termination of the study, sunshine bass (611.1 g) and palmetto bass (517.8 g) had significantly greater mean weights than white bass (254.4 g). Significant differences among all three taxonomic groups were found for h and for mean daily growth rate. Both crosses of hybrid striped bass had lower feed conversion ratios when compared with white bass. Relative weight values (ratio of a fish\u27s weight to the weight of a standard fish of the same length) for sunshine bass were significantly greater than values for palmetto bass and white bass. Survival rates ranged from 98% to 100% for the three taxonomic groups. Differences were not detected between sunshine bass and palmetto bass for eviscerated percentage, headed and eviscerated percentage, or dressout percentage. Sunshine bass outperformed palmetto bass at phase II and phase III sizes under the conditions of this study

Five-Dimensional Unification of the Cosmological Constant and the Photon Mass

Using a non-Riemannian geometry that is adapted to the 4+1 decomposition of space-time in Kaluza-Klein theory, the translational part of the connection form is related to the electromagnetic vector potential and a Stueckelberg scalar. The consideration of a five-dimensional gravitational action functional that shares the symmetries of the chosen geometry leads to a unification of the four-dimensional cosmological term and a mass term for the vector potential.Comment: 8 pages, LaTe

Evaluation of Natural-Source Vitamin E, RRR-α-Tocopheryl Acetate, as a Micronutrient in Sunshine Bass Feed

A variety of vitamin E isomers can be used in the manufacture of animal feeds, though the efficacy of these sources varies. Our purpose was to evaluate natural-source vitamin E, RRR-a-tocopheryl acetate (NSVE), as an alternative to synthetic vitamin E, all-rac-a-tocopheryl acetate (SYNE), in the diets of sunshine bass (female white bass Morone chrysops X male striped bass M. saxatilis). Our specific objectives were to evaluate graded levels of NSVE in terms of meeting the vitamin E requirement of sunshine bass and to address the physiological and economic suitability of NSVE by direct comparison with SYNE. Five isocaloric, isonitrogenous, semipurified diets were prepared and supplemented with NSVE at 0, 10, 20, or 30 mg/kg or SYNE at 30 mg/kg. Each dietary treatment was fed to fish in four replicate tanks, each housing 10 juvenile sunshine bass (mean weight = 25.1 g) in a recirculating system. One-way multiple analysis of variance (MANOVA) indicated that significant differences among treatment groups (Wilks’ λ = 0.006) were most greatly attributable to differential survival, growth, food conversion ratio, and liver aldehyde concentration. Fish fed diets containing NSVE at less than 22 mg/kg (as-fed concentration, or 20 mg/kg supplemental dietary treatment) exhibited significantly lower survival (≤65% versus ≥92%) and weight gain (≤359% versus ≥591%), impaired food conversion ratio (2.9 versus ≤1.9), and evidence of heightened liver tissue oxidation (aldehyde, 0.62 nmol/g of tissue versus ≤0.22 nmol/g). Fish fed diets containing an NSVE as-fed concentration of 22 mg/kg or more exhibited performance equivalent to those fed the SYNE control within all parameters. Accordingly, we conclude that NSVE is as effective as SYNE, but at lower concentrations, and that it may be of greater value as a micronutrient source for aquaculture feeds